This study proposes to continue follow-up of a cohort of patients with new onset ESRD who were recruited between 1995 and 1998. The purpose of the project now shifts from comparing outcomes between hemodialysis and peritoneal dialysis patients (the aim of the original project) to studying of the relation between a variety of process measures and patient outcomes. Outcomes include mortality, quality of life, patient satisfaction, and development of comorbid conditions. The primary study cohort consists of patients cared for by a chain of non-profit dialysis centers (80 participating centers). This chain has an ongoing research relationship with the study investigators and with the parent institution, Johns Hopkins. Annual self- administered patient surveys and chart review will provide most of the outcomes information and some data on care processes. The principal source of information on care processes, however, will be an annual survey sent to the directors of the 80 participating centers inquiring about a wide variety of care practices. Several hypotheses relating processes to outcomes are given in the specific aims section. The investigators also propose to conduct ancillary, confirmatory analyses using automated data but no primary data collection in a much larger cohort of prevalent cases from these same centers. The same director survey will provide information on care processes as predictors. Outcomes are limited to survival.